1. Field of the Invention
This invention relates generally to a videophone and, more particularly, to a videophone with a TV camera detachable in such a manner that the operation of the videophone is greatly facilitated.
2. Prior Art
A typical conventional videophone is shown in the perspective view of FIG. 1 in which a TV camera 2 is incorporated in a videophone unit 1, the photosensitive surface of TV camera 2 being disposed on a front surface 3. The videophone unit 1 is provided with a CRT display 4 which functions as an image display means for displaying image data picked-up by a user's own TV camera 2 or image data transmitted from the videophone of another party during video telephone communication via a telephone line. The display surface of the CRT display 4 is disposed on a front surface 3. Variety operation buttons 5 are also provided on the front surface 3.
FIG. 2 is a block diagram depicting the internal constitution of a videophone. In FIG. 2, an image control unit 11 controls the image data picked-up by TV camera 2 and the image data read from an image memory 12. The thus controlled image data are supplied and displayed on CRT display 4. Subsequently, the image data are also delivered to image memory 12 and stored therein.
A group of multiple switches 13 is turned ON/OFF by various operation buttons 5 (FIG. 1). Based on switching signals from switch group 13, a microcomputer 14 functions to take the image data out of image control unit 11 to an image transmission unit 15, and vice versa.
A line interface 16 selectively connects image transmission unit 15 and a telephone 17 to a telephone line 18. The numeral 19 represents a power supply for the videophone unit. It is noted that the image control unit 11 and microcomputer 14 are combined to constitute an image processing unit 20.
The description will next deal with the operation of the videophone. The data of the user's own image formed by TV camera 2 is taken into image control unit 11 and undergoes an inversion process in accordance with a command issued from microcomputer 14 on the basis of the switch signals transmitted from switch group 13. Subsequent to this step, the image data is displayed as a reflected image on CRT display 4.
More specifically, the user's face which faces the videophone 1 is imaged as a true image (the user's face as viewed by the other party) by means of TV camera 2. If the true image were to be displayed directly on the CRT display 4, however, the user who is accustomed to looking at his own image in a mirror may feel it to be quite unnatural. It is thus required that the image be displayed as a reflected image on the CRT display 4. Consequently the abovementioned inversion display is effected.
The image data obtained when imaging a subject other than the user himself by use of TV camera 2 is displayed as a true image directly on CRT display 4 without effecting inversion. Similarly displayed on CRT display 4 is the image data transmitted from the other party in the ongoing video telephone communication to the image control unit 11 via the telephone line, line interface 16, image transmission unit 15 and microcomputer 14.
On the other hand, when transmitting the image data of the user's image formed by TV camera 2 to the other party, the image data from TV camera 2 is temporarily stored in image memory 12 through image control unit 11.
Subsequently, the image data read from image memory 12 is transmitted to the other party via microcomputer 14, image transmission unit 15, line interface 16 and telephone line 18. The image data is then displayed as a true image on the CRT display 4 of the other party.
The thus constructed prior art videophone system is attended by the following problems. If, in addition to the user's face, another subject, e.g., a child who is playing nearby is to be shown, the videophone unit itself has to be moved to direct the TV camera toward the freely moving target subject, because the TV camera is integrally incorporated therein. It is thus rather difficult to direct the TV camera to a target subject.
Accordingly, it is a primary object of the present invention to obviate the foregoing problems and to provide a novel videophone capable of readily directing a TV camera toward a target subject for bringing into focus that target without moving the whole videophone unit, and which is also capable of displaying the user's image as a reflected image while displaying images other than the user's image as true images.